Toroidal deflection yoke having conductors wound in flyback manner

ABSTRACT

The active field producing conductor turns on the inside generally cylindrical core surface of a multilayer toroidal deflection yoke are wound in one direction, e.g., clockwise. The return conductors on the outside of the core are wound in a flyback manner for enabling conductors to be placed in a second layer between the conductors of the first layer for forming a higher conductor distribution density for a first coil or for interleaving the conductors of a second coil between the conductors of the first coil. The two layers may thus be wound over a large angular portion of the core without stopping the winding machine for the cutting or tying of conductors within each coil.

United States Patent [1 1 Over et al.

1 1 3,757,262 [4 1 Sept. 4, 1973 TOROIDAL DEFLECTION YOKE HAVING CONDUCTORS WOUND IN FLYBACK MANNER [75] Inventors: Donald Paul Over; Ira Foy Thompson, both of Indianapolis, Ind.

[73] Assignee: RCA Corporation, New York, N.Y.

[22] Filed: Feb. 28, 1972 [21] App]. No.: 229,829

[52] US. Cl. 335/213, 335/210 124 e BIOI Primary ExaminerGeorge Harris Attorney-Eugene M. Whitacre and Paul J. Rasmussen 5 7] ABSTRACT The active field producing conductor turns on the inside generally cylindrical core surface of a multilayer toroidal deflection yoke are wound in one direction, e.g., clockwise. The return conductors on the outside of the core are wound in a flyback manner for enabling conductors to be placed in a second layer between the conductors of the first layer for forming a higher conductor distribution density for a first coil or for interleaving the conductors of a second coil between the conductors of the first coil. The two layers may thus be wound over a large angular portion of the core without stopping the winding machine for the cutting or tying of conductors within each coil.

5 Claims, 4 Drawing Figures l O O O I I I I? I9 I11 2| 20 23 22 25% 26 FINISH 001* Pmmzum' 3.757. 262

sum 2 or 3 FINISH com FINISH colfiz Fig. 3.

3mm c0101 TOROIDAL DEFLECTION YOKE HAVING CONDUCTORS WOUND IN FLYBACK MANNER BACKGROUND OF THE INVENTION This invention relates to a toroidal deflection yoke and a method for winding it utilizing conductor turns wound in a flyback manner.

It is known that toroidal deflection yokes can be used in place of saddle-type deflection yokes in a color television receiver to provide the magnetic fields for causing a plurality of electron beams to scan a raster on the picture tube. Toroidal deflection yokes have an advantage over the saddle-type yokes in that less copper wire is required to produce the required deflection fields. Furthermore, it is possible to wind toroidal deflection yokes with great precision for providing the precise magnetic field for deflecting the color television electron beams without distorting the raster or the beam bundles formed by the beams.

As taught in copending application Ser. No. 95,847, now issued as U.S. Pat. No. 3,668,580, filed on Dec. 7, 1970, for Robert L. Barbin and entitled, TOROIDAL DEFLECTION YOKE HAVING ASYMMETRICAL WINDINGS, a toroidal deflection yoke is provided including vertical and horizontal deflection coils which have portions thereof interleaved for providing a deflection field with certain characteristics. The particular yoke disclosed in that application also has an asymmetry of coil conductor turns in the four quadrants of the yoke. While the advantages of having interleaved winding precision deflection yokes are recognized, it is equally important for the yoke manufacturer to be able to wind a particular yoke distribution quickly and economically.

In the past toroidal yokes have been wound with the winding machine being stopped at the end of a number of successive conductor turns for the purpose of pulling an electrical tap from the windings, cutting the conductor for later joining with another portion of the coil, or for fastening the conductor in place on the yoke so that it remains fixed as the succeeding yoke portions are wound. All of these operations take time as the operator must stop the machine and perform the operation before proceeding with the winding of the yoke. Subsequent joining of the separate coil portions, such as by soldering the end conductor turns together, takes more time and the result is a relatively long production time for each yoke which, in turn, increases the cost of the yoke and the television receiver in which the yoke is to be utilized.

It is an object of this invention to provide a deflection yoke utilizing conductors wound in a flyback manner for allowing the continuous winding of overlapping and separated portions of a deflection yoke coil.

Another object of the invention is to provide a method for winding the coil of a deflection yoke utilizing conductors wound in a flyback manner to enable continuous winding of overlapping and interleaved portions of a deflection yoke coil.

In accordance with the invention a toroidal deflection yoke is provided in which a multi-layer deflection coil is toroidally wound about a generally cylindrical hollow flared core. The coil conductor is wound over an angular segment of the core for providing a first layer of conductor turns around the small diameter end of the core and to provide a single layer of more widely separated conductor turns around the large diameter end of the core. The conductor is returned along the outside of the core from the end position of the angular segment to a space near the beginning of the segment to form a second layer of turns of the small diameter portion of the core and to fill in, in an interspersed manner, the spaces between the first wound conductor turns at the large diameter end of the core.

A method is provided for winding the yoke described above in which the conductor is toroidally wound around the core, forming a first layer of conductors at one end of the core and a single layer of conductor turns at the other end of the core, the conductor being returned in a flyback manner from the last wound turn for forming a second layer of turns over the first layer at the one end of the core and for interspersing turns between the first wound turns of the single layer at the other end of the core.

A more detailed description is given in the following specification and accompanying drawings, in which:

FIG. 1 is a partial cross-sectional view of a toroidal deflection yoke suitable for embodying the invention;

FIG. 2 is a partial sectional view looking from the rear to the front of the yoke shown in FIG. 1;

FIG. 3 illustrates the placement of the conductor turns in a deflection yoke according to the invention; and

FIG. 4 shows another embodiment of the placement of conductor turns in a deflection yoke according to the invention.

DESCRIPTION OF THE INVENTION FIG. 1 is a partial cross-sectional view of a toroidal deflection yoke suitable for embodying the invention. A hollow generally cylindrical flared ferrite core 10 includes end caps 11 and 13 of plastic-type material disposed over the small and large diameter ends of the core. The annular end cap 11 includes a plurality of slots 12 to engage the conductor turns to be wound around the core such that as the conductor is drawn taut by the winding machine, the conductor turn will be securely held in place. By fixedly placing the conductors in this manner, the degree of precision required of the winding turns distribution is assured and the repeatability of the conductor winding distribution from one yoke to another is similarly assured. The annular end cap 13 at the front of the yoke includes a plurality of slots 14 to hold the conductor turns in position at the front of the yoke.

A plurality of conductor turns 15 is wound toroidally about the core 10 and the end caps 11 and 13 to form two pairs of horizontal and two pairs of vertical deflection coils. The appropriate end turns of the two pairs of coils are suitably connected to connect the respective coils in series or parallel for being driven by suitable sources of scanning current.

FIG. 2 is a partial cross-sectional view looking from the small diameter end to the large diameter end of the yoke shown in FIG. 1. FIG. 2 illustrates how a single layer of conductors 15 at the large diameter end of the core 10 becomes bunched together at the small diameter end to form two layers. The conductors 15 marked with an X" are wound in adjacent slots 12 of the end cap 11 at the small diameter end of the core. These conductor turns fan outwardly from each other as they approach the large diameter end of the core to maintain the same angular spacing between conductors as existed at the small diameter end. The unmarked conductors forming the second layer of conductor turns at the small diameter end are interspersed between the marked conductor turns, the marked and unmarked conductor turns forming a single layer at the large diameter end.

In the past, in the winding of toroidal yokes such as illustrated in FIGS. 1 and 2, the first layer of conductor turns at the small diameter end was wound all the way around the core, leaving appropriate spaces between adjacent conductors if interleaved vertical and horizontal coils are desired. Then the second layer of conductors turns at the rear was wound on top of the first. After this second layer was wound, the respective layers were cut at appropriate places and the conductor ends joined for forming the desired coil winding distribution. These operations were in addition to the stopping of the coil winding machine at least once during the winding of each layer for the purpose of reclamping so that the conductor turns could be wound around the entire core.

FIG. 3 illustrates the placement of conductor turnsin a deflection yoke according to the invention. FIG. 3 serves to illustrate the physical arrangement of the conductors forming vertical and horizontal coils around a portion of the core. Although only two coils are illustrated in FIG. 3, for example, coil 1 may be a horizontal deflection coil and coil 2 may be a vertical deflection coil, it is to be understood that the placement of conductor turns around the remainder of the core is similar to that shown and would form the other pair of deflection coils required to complete the yoke.

In FIG. 3 the numbered circles and the lines connecting them indicate the conductor turns forming a coil 1. The numbered triangles and the lines connecting them indicate the conductor turns forming coil 2. The solid lines connecting the respective circles and triangles represent conductor turns on the outside of the core. The dotted lines connecting the respective circles and triangles represent the conductor turns on the inside of the core. In the actual physical embodiment of the yoke, the inside conductor turns represented by the dotted lines are placed adjacent each other and there is no crossing of one conductor over another. This provides a relatively smooth inside surface of the core for providing the desired deflection field and for positioning the yoke closely to the flared glass envelope of the color television picture tube if desired.

An understanding of the sequence of winding in accordance with the invention will be readily understood if it is remembered that the numbered circles are first wound in numerical sequence and then the numbered triangles are wound in numerical sequence. A numbered circle or triangle at the top of FIG. 3, representing the rear of the core or the small diameter end of the core, is always connected to the corresponding number at the bottom of FIG. 3, representing the front or large diameter end of the core. These conductors from the rear to the front are on the inside of the core and, to simplify the drawing, are shown in dotted lines only at the beginning and end of each coil. The conductors on the outside of the core are wound from the front of the core to the rear, represented by the solid lines in FIG. 3. From the front of the core the solid lines always connect to the next succeeding higher numbered circle or triangle at the rear of the core.

In FIG. 3 the first coil is started at the circle I at the rear or small diameter portion of the yoke and the conductor, following the dotted line, is brought along the inside surface of the yoke to a position indicated by circle l at the bottom of the figure, illustrating the front or large diameter portion of the yoke. From this position the conductor is brought along the solid line on the outside of the yoke back to the rear of the yoke to position 2. From this position the wire is again brought on the inside of the yoke adjacent the first turn to position 2 at the front of the yoke and from there back along the outside of the yoke to position 3 at the rear. It should be noted how the first and second turns are wound adajcent each other on both the inside and outside portions of the core. However, from the circle 2 at the front of the core, the conductor is wound in a flyback manner to circle 3 at the rear of the yoke, which circle is located between the first and second conductors. To achieve this during actual winding of the yoke on a toroidal core winding machine, the yoke is advanced clockwise from position 1 to position 2 as the wire is brought along the outside of-the core. From position 2 at the front of the yoke, the core is rotated a half position counterclockwise to provide the flyback return conductor on the ouside of the core leading to position 3 at the rear.

As illustrated in FIG. 3, the two rows of conductor positions at the rear or small diameter end of the core are interleaved. This represents the two-layer arrangement at the rear of the core, which was described in conjunction with FIG.v 2 as it actually appears on the yoke. Thus the top one of the two layers at the rear of the core in FIG. 3 represents the outside or second layer of conductors illustrated in FIG. 2.

From FIG. 3 at the rear of the yoke the conductor turns are wound in a similar short flyback manner in numerical sequence all the way through the turn represented by the circle 15 at the large end of the core. To simplify the drawings the dotted lines representing the noncrossed conductor turns on the inside of the core have been eliminated, but it is to be understood that the dotted lines would run from each numbered circle at the small end of the core to the corresponding numbered circle at the large end of the core. At the circle 15 at the large diameter end or front of the core, it is desired to produce a separation of the conductor turns of coil 1 so that conductors turns of another coil, coil 2, may be placed within the separation of providing the desired interleaved winding distribution. To achieve this the conductor turn on the outside of the core from circle 15 at the front of the core is advanced several spaces to a position represented by the circle 16 at the rear of the core. This is achieved by advancing the core clockwise the desired number of spaces, while the conductor is beingwound on the outside of the core from the circle 15 at the front to circle 16 at the rear.

From the position 16 at the rear of the core, the conductor turns of coil 1 are wound without interruption and with the short flyback arrangement through conductor turn 27 at the front end of the core, which turn represents the end conductor of the illustrated coil 1. At this point the winding process is stopped and the machine rotates the core counterclockwise back to a position where coil 2 may be started to be wound.

Coil 2 is wound in a similar manner to coil 1. After going through two conductor turns of coil 2, represented by the numbered triangles 1 and 2 at the left of FIG.3, the core is advanced clockwise to triangle 3 at the rear or small diameter end of the core with the conwinding arrangement enables the two layers of conductors at the rear to be wound at one time, thereby eliminating the requirement of having to first wind the first layer, cutting the wire and going back to wind the second layer in order to complete the coil which occupies at least two layers at the rear of the core.

FIG. 4 shows another embodiment of the placement of conductor turns in a deflection yoke according to the invention. In FIG. 4 the conductor winding distribution on the inside of the core, which portion of conductors produces the required magnetic deflection field, is the same as that shown in FIG. 3. The difference between the FIG. 3 and FIG. 4 embodiments is that in FIG. 4 the conductors are not wound in a flyback manner after every second consecutive turn. Rather in FIG. 4 considerably more conductor turns are wound before the flyback winding which fills in the second conductor layer at the rear of the core and the empty spaces between the separated conductors in the single layer at the front of the core. In FIG. 4, coil 1, represented by the numbered circles, is wound sequentially from circle 1 at the rear of the core through circle 7 at the front of the core. From circle 7 al the front the conductor is wound in a flyback manner to circle 8 at the rear of the core as the core is rotated counterclockwise to this position. From circle 8 at the rear, which starts the second layer of conductors at the rear and which will fill in the spaces between the conductor turns at the front of the core, coil 1 continues to be wound clockwise through circle at the front of the core. From circle 15 the core is advanced clockwise as the conductor is wound to circle 16 at the rear of the core. From circle 16 at the rear through circle 27 at the front, coil 1 is wound sequentially and with a flyback to complete the illustrated coil 1 at circle 27 at the front of the core.

The core is then rotated counterclockwise back to the left of FIG. 4 so that coil 2, represented by the numbered triangles, may be wound. Two turns of coil 2 are sequentially wound followed by a clockwise advance of the core to triangle 3 at the rear of the core. From triangle 3 at the rear of core coil 2 is sequentially wound through triangle 7 at the front at which time the core is rotated counterclockwise to wind the conductor in a flyback manner to triangle 8 at the rear. From this point the turns are again wound sequentially through triangle 12 at the front of the core which is the end of coil 2.

Although the winding distribution has been described with the coil windings progressing with clockwise rota tion of the core as viewed from the small diameter end 7 of the core, it is to be understood that the winding could be accomplished by counterclockwise rotation as well. The particular interleaving of coil 1 and coil 2 conductors is merely illustrative and it can be seen that any desired interleaving of coil conductors may be accomplished in accordance with the invention.

The angular segments of the core over which the coils 1 and 2 extend may comprise as much of the perimeter of the core as desired with the limitation that the core must be reclamped before the entire yoke can be wound. One convenient way of winding a deflection yoke in accordance with the invention is to initially clamp the core in the winding machine, wind all of one horizontal coil and then a part of the second horizontal coil. The extent of the winding of the second horizontal coil is limited by the core clamping mechanism. The core is then reclamped; for example, the clamp is placed degrees around the core from the initial position. The remainder of the second horizontal coil is then wound. Without reclamping at this time, one complete vertical coil is then wound, and a part of the. second. The clamp is then moved back to where it was originally and the remaining portion of the second vertical coil is wound to complete the winding of the yoke. To make the operation even more efficient, the conductor does not have to be cut between the winding of the first and second horizontal or vertical coils. An extra turn can be wound between the finish of one coil and the start of the other and during the winding cycle or later, when the finished yoke is removed from the winding machine, this extra turn can be cut to form the separate coils. It may be desirable to utilize different color wire for the vertical and horizontal coils, especially if they are interleaved, to make it easy for the operator to properly cut and connect the respective coils.

Although for simplicity the invention was described illustrating two layers of conductors at the rear of the core and a single layer at the front, it is to be understood that the flyback manner of winding multiple layers of a coil without stopping the machine or cutting the conductor may be extended to three or more layers in the rear of the core and two or more layers at the front of the core.

What is claimed is:

1. A toroidal deflection yoke, comprising:

a generally cylindrical hollow flared core;

a pair of horizontal and a pair of vertical deflection coils wound toroidally about said core, said coils comprising at least two layers of conductor turns at the small diameter portion of said core and a single layer at the large diameter portion of said core;

said conductor being wound over an angular segment of said core to occupy successive conductor receiving portions in a first layer around the small diameter portion of said core and to occupy every other conductor receiving portion in said single layer around the large diameter portion of said core, said conductor being returned along the outside of said core from the end position of said angular segment to a space near the beginning of said segment to form a second layer of conductor turns at the small diameter portion of said core and to lie between said first wound conductor turns at the large diameter portion of said core.

2. A toroidal deflection yoke, comprising:

a hollow generally cylindrical flared core;

a pair of horizontal deflection coils having portions thereof interleaved between portions of a pair of vertical deflection coils wound toroidally about said core, the conductor turns comprising said coils forming at least first and second layers of turns at the small diameter end of said core and at least a single layer of turns at the large diameter end of said core;

conductor turns forming a first horizontal coil portion along an angular segment of said core being wound over a first portion of said segment occupying adjacent conductor receiving portions in said first layer at said small diameter end of said core and occupying every other conductor receiving coil portions and having a turns arrangement similar to said first horizontal coil portion.

forming at least first and second layers of turns at the small diameter end of said core and at least a single layer of turns at the large diameter end of said core;

portion at said large diameter end of said core, the conductor turns forming a first vertical coil portion last turn of said portion of said angular segment I along an angular segment of said core being wound being wound in a flyback manner back to a region over a first portion of said segment occupying adjanear the start of said portion of said angular segcent conductor receiving portions in said first layer ment and wound for forming said second layer of at said small diameter end of said core and occupyturns at said small diameter end of said core and for 10 ing every other conductor receiving portion at said completing said single layer of turns at said large large diameter end of said core, the last turn of said diameter end of said core, said conductor being adportion of said angular segment being wound in a vanced from said first portion of said segment to a flyback manner back to a region near the start of second portion of said angular segment separated said portion of said angular segment and wound for from said first portion for forming a second horiforming said second layer of turns at said small dizontal coil portion having a conductor turns arameter end of said core and for completing said rangement similar to said first horizontal coil porsingle layer of turns at said large diameter end of tion; and said core, said conductor being advanced from said a vertical coil portion being wound within the separafirst portion of said segment to a second portion of tion around said core between said first and second said angular segment separated from said first portion for forming a second vertical coil portion having a conductor turns arrangement similar to said layer of horizontal coil portion turns.

first vertical coil portion; and

a horizontal coil portion being wound within the separation around said core between said first and second coil portions and having a turns arrangement similar to said first vertical coil portion.

5. A toroidal deflection yoke according to claim 4 wherein said second layer of conductor turns of at least said first portion of said vertical coil extends over a lesser angular segment portion than the turns of said first layer and wherein said horizontal coil portion comprises turns wound in said second layer over said first layer of vertical coil portion turns. 7

3. A toroidal deflection yoke according to claim 2 wherein said second layer of conductor turns of at least said first portion of said horizontal coil extends over a 25 lesser angular segment portion than the turns of said first layer and wherein said vertical coil portion comprises turns wound in said second layer over said first 4. A toroidal deflection yoke, comprising:

a hollow generally cylindrical flared core;

a pair of horizontal deflection coils having portions thereof interleaved between portions of a pair of vertical deflection coils wound toroidally about said core, the conductor turns comprising said coils 

1. A toroidal deflection yoke, comprising: a generally cylindrical hollow flared core; a pair of horizontal and a pair of vertical deflection coils wound toroidally about said core, said coils comprising at least two layers of conductor turns at the small diameter portion of said core and a single layer at the large diameter portion of said core; said conductor being wound over an angular segment of said core to occupy successive conductor receiving portions in a first layer around the small diameter portion of said core and to occupy every other conductor receiving portion in said single layer around the large diameter portion of said core, said conductor being returned along the outside of said core from the end position of said angular segment to a space near the beginning of said segment to form a second layer of conductor turns at the small diameter portion of said core and to lie between said first wound conductor turns at the large diameter portion of said core.
 2. A toroidal deflection yoke, comprising: a hollow generally cylindrical flared core; a pair of horizontal deflection coils having portions thereof interleaved between portions of a pair of vertical deflection coils wound toroidally about said core, the conductor turns comprising said coils forming at least first and second layers of turns at the small diameter end of said core and at least a single layer of turns at the large diameter end of said core; conductor turns forming a first horizontal coil portion along an angular segment of said core being wound over a first portion of said segment occupying adjacent conductor receiving portions in said first layer at said small diameter end of said core and occupying every other conductor receiving portion at said large diameter end of said core, the last turn of said portion of said angular segment being wound in a flyback manner back to a region near the start of said portion of said angular segment and wound for forming said second layer of turns at said small diameter end of said core and for completing said single layer of turns at said large diameter end of said core, said conductor being advanced from said first portion of said segment to a second portion of said angular segment separated from said first portion for forming a second horizontal coil portion having a conductor turns arrangement similar to said first horizontal coil portion; and a vertical coil portion being wound within the separation around said core between said first and second coil portions and having a turns arrangement similar to said first horizontal coil portion.
 3. A toroidal deflection yoke according to claim 2 wherein said second layer of conductor turns of at least said first portion of said horizontal coil extends over a lesser angular segment portion than the turns of said first layer and wherein said vertical coil portion comprises turns wound in said second layer over said first layer of horizontal coil portion turns.
 4. A toroidal deflection yoke, comprising: a hollow generally cylindrical flared core; a pair of horizontal deflection coils having portions thereof interleaved between portions of a pair of vertical deflection coils wound toroidally about said core, the conductor turns comprising said coils forming at least first and second layers of turns at the small diameter end of said core and at least a single layer of turns at the large diameter end of said core; conductor turns forming a first vertical coil portion along aN angular segment of said core being wound over a first portion of said segment occupying adjacent conductor receiving portions in said first layer at said small diameter end of said core and occupying every other conductor receiving portion at said large diameter end of said core, the last turn of said portion of said angular segment being wound in a flyback manner back to a region near the start of said portion of said angular segment and wound for forming said second layer of turns at said small diameter end of said core and for completing said single layer of turns at said large diameter end of said core, said conductor being advanced from said first portion of said segment to a second portion of said angular segment separated from said first portion for forming a second vertical coil portion having a conductor turns arrangement similar to said first vertical coil portion; and a horizontal coil portion being wound within the separation around said core between said first and second coil portions and having a turns arrangement similar to said first vertical coil portion.
 5. A toroidal deflection yoke according to claim 4 wherein said second layer of conductor turns of at least said first portion of said vertical coil extends over a lesser angular segment portion than the turns of said first layer and wherein said horizontal coil portion comprises turns wound in said second layer over said first layer of vertical coil portion turns. 